Large binding lines typically include a number of binding line components, including, for example, a gatherer, which gathers signatures to be collated into a printed book in a particular order, a stitcher, which staples or stitches the signatures together, and a trimmer, which trims the stitched signatures to a predetermined size to produce a finished book. Typically, binding lines also include a mail table which addresses the finished books, sorts the addressed books by, for example, zip code and/or carrier route, and bundles the sorted books together for shipping.
It is commonly known to power all of the individual binding line components using a single shaft driven by a single motive power source. Typically, the binding line components are permanently coupled to the shaft via separate drive systems which include a number of pulleys and belts or chains and which operate the associated binding line components at predetermined speeds dependent on the speed of the shaft. Such drive systems are considered inadequate, however, for a couple of reasons. First, the entire binding line must be operated in order to perform a job on a single binding line component, such as the mail table. Consequently, individual operation of a binding line component is expensive and time consuming. Second, only one person can perform a make-ready or a calibration procedure on a binding line having permanently configured drive systems because movement of a first binding line component causes movement of the shaft which, in turn, causes movement within the other the binding line components and, thereby, presents a safety hazard to anyone working on the other binding line components.
It is also known to provide reconfigurable drive systems within a binding line. Some of these reconfigurable drive systems, however, require an operator to adjust certain components thereof, such as drive chains, belts and/or pulleys, in order to decouple the drive system, and hence, the associated binding line component, from the shaft. These manually adjustable drive systems are considered inadequate because they require a high level of expertise on the part of the operator and because they require a large amount of time to be decoupled from the shaft.
Other drive systems which are capable of being decoupled from the shaft include clutch mechanisms. These drive systems are considered inadequate, however, because they are relatively complex and expensive, require a large amount of space, include many moving parts and, consequently, require a high level of maintenance. Furthermore, the clutch mechanisms of these drive systems typically include one or more sets of bearings, the failure of which may cause the clutch to inadvertently engage and couple the associated binding line component to the shaft. The resulting inadvertent and unexpected operation of certain binding line components, such as the trimmer, which includes sharp cutting elements, presents a serious safety hazard.